1. Field of the Invention
The present invention relates to an actuator utilizing arm displacements of a silicon structure having a piezoelectric device attached thereto, and a method of making the same. In particular, the present invention relates to an actuator suitable for controlling the position of a magnetic head in a magnetic recording apparatus with high precision and so forth, and a method of making the same.
2. Related Background Art
In recent years, magnetic recording density has been improving at a very rapid rate. Therefore, the track pitch width has been narrowed so as to increase the density, which makes it necessary to improve the precision in regulating the magnetic head position with respect to track positions. However, there is a limit to the magnetic head position regulation when depending on the control of a VCM (voice coil motor) alone. Hence, a two-stage servo control system utilizing a VCM and an actuator for carrying out finer control has been proposed.
Conventionally known as an actuator for use in the two-stage servo control system are zirconia frame actuators and metal frame actuators (disclosed in Japanese Patent Application Laid-Open No. 2002-289936, for example).
A zirconia frame actuator is obtained by a method comprising the steps of forming a laminated zirconia sheet with a piezoelectric device by printing or the like, firing the resulting product, and then cutting the fired product into a device size. This actuator is advantageous in that its shock resistance is improved by the use of zirconia.
For making a metal frame actuator, a stainless sheet is initially etched or punched, so as to form a slider mount, a part to be secured to a suspension, and a pair of driving parts (arms) to which a piezoelectric device is attached. Subsequently, each driving part is bent so as to become perpendicular to the slider mount, and a piezoelectric device is attached to the outer side of each driving part. This yields an actuator having a main part integrally formed from a metal. The integral forming can reduce the number of components, while improving production efficiency.